There are many situations in which it is desirable to maximize the range of an air vehicle. This can generally be accomplished by maximizing the amount of fuel that can be carried by the vehicle and minimizing the weight of the vehicle itself. One type of air vehicle that can carry a large amount of fuel relative to its size and weight is a high aspect ratio aircraft in which the wings are loaded with fuel. "High aspect ratio" refers to aircraft which have long wing spans from wing tip to wing tip relative to the mean wing chord. In other words, the wings are relatively long in the lateral direction and narrow between their leading and trailing edges.
During flight, high aspect ratio wings are aerodynamically supported. However, when the wings are fully loaded with fuel for take-off, the wing fuel load tends to cause the long slender wings to bend. Therefore, the wings need to be supported to control wing bending and enable take-off of the aircraft.
One way of providing the required support for the wing fuel load is to equip the aircraft with permanent take-off and landing gear mounted on the wings. This approach adds a good deal of weight to the aircraft and, therefore, reduces its range. The effect on the aircraft's range can be mitigated by detachably mounting the gear on the aircraft wings to allow it to be jettisoned after take-off. A system with jettisonable gear helps maintain the range but has the disadvantages of being relatively complex, expensive, and cumbersome to use.
During the last several decades, there have been a number of proposals for assisting the launch of aircraft by means of ground based vehicles. Some of the vehicles that have been proposed have been designed to allow either the complete elimination of landing gear or significant reductions in the size and complexity of the gear, which would be required to function only during landing when the aircraft is much lighter than at take-off. The present invention addresses the inadequacies of known types of aircraft launch devices. The invention is primarily concerned with the problem of the unsuitability of known devices for launching high aspect ratio aircraft with wing fuel loads.